Which nutrient protects us from diseases?

Concept: Nutrients required by the human body are classified by their primary physiological function into three groups — energy-giving nutrients (carbohydrates and fats), which are oxidised to release energy for the body's activities; body-building nutrients (proteins), which supply amino acids for growth and tissue repair; and protective nutrients (vitamins and minerals), which regulate body processes, support the immune system, and prevent deficiency diseases.

Application: This question tests the standard classification of nutrients into three functional groups by primary physiological role: energy-giving (carbohydrates and fats), body-building (proteins), and protective (vitamins and minerals) — the protective group is the one associated with strengthening immunity and guarding against deficiency diseases such as scurvy (linked to vitamin C), anaemia (linked to iron), and goitre (linked to iodine). The question asks which group carries this protective classification, and only the vitamins-and-minerals option is classified that way.

Cross-check: contrasting each option against this classification confirms this:

• Fats and carbohydrates are classified under the energy-giving group in this framework — their defined role is supplying heat and energy, not the protective classification.

• Protein is classified under the body-building group in this framework — its defined role is tissue growth and repair, not the protective classification.

• The framework assigns each of the three functional groups a single primary label; only the vitamins-and-minerals group carries the protective label, so grouping all three together does not match the classification.

Result: Vitamins and minerals are classified as the protective nutrients that protect the body from diseases.